Generation of ordered phage sublibraries of YAC clones: construction of a 400-kb phage contig in the human dystrophin gene.

A phage contig of 400 kb that extends from the brain-specific promoter at the 5'-end of the human dystrophin gene, through the muscle-specific promoter over 100 kb further downstream, and across most of intron 1 has been assembled. To achieve this, a yeast artificial chromosome (YAC) subcloning approach was used. Total DNA from a yeast strain containing a 400-kb YAC from the dystrophin gene was cloned using a lambda phage vector containing RNA polymerase promoters flanking the cloning sites. Phage containing human DNA inserts were then ordered into an overlapping set by hybridization of end-specific RNA probes from individual clones back to plaque lifts of gridded phage subclones. The clones generated will be useful as reagents for detailed structural and functional analyses of this region of the dystrophin gene.